Straw chopper having pivoted blades



May 30, 1961 A. A. WHITE STRAW CHOPPER HAVING PIVOTED BLADES Filed April 5, 1958 2 Sheets-Sheet 1 INVENTOR. A'Y/ev Ana real /i/fi May 30, 1961 A. A. WHITE STRAW CHOPPER HAVING PIVOTED BLADES 2 Sheets-Sheet 2 Filed April 3, 1958 INVENTOR. 4/1877 Ina re M A,

United States Patent STRAW CHOPPER HAVING PIVOTED BLADES Allen Andrew White, Peabody, Kans., assignor to Hesston Manufacturing Co., Inc., Hesston, Kans., a corporation of Kansas Filed Apr. 3, 1958, Ser. No. 726,255

7 Claims. (Cl. 146-121) This invention relates to a material treater particularly adapted to comminute material as by chopping, beating, or cutting, the primary object being to provide a novel arrangement of parts for eifecting improved results, increasing the over-all life of the components of the machine and reducing the power requirements for operating the same.

Comminuting mills in the nature of those having hingedly mounted hammers that act upon material by impact, have been used for many years and even in the field to which the instant invention specifically relates, i.e., the chopping and spreading of straw emanating from a combine or the like.

By virtue of the fact that such apparatus divides the material in small particles by impact rather than by cutting, the machine must rely upon the mass characteristics of the hammers for carrying out its intended functions. The combined weight of the relatively large number of heavy, blunt hammers makes it necessary to use a rather large power supply because considerable energy is needed, particularly to initiate rotation from a standstill or slow-down condition.

The purpose of the hinge connection for the hammers themselves is to permit the same to yield, in a direction counter to the direction of rotation of the apparatus, to excessive resistance presented by an overload of the material, such retrograde swinging movement of the hammers permitting continued and substantially uninterrupted rotation. Nonetheless, the speed of rotation is retarded from time to time, forcing the machine to call upon added power which must be kept in reserve.

In order to alleviate the difiiculties above set down, apparatus of this type has oftentimes been supplied with sharpened hammers to present cutting knives, and in some instances, the swinging knives cooperate with stationary blades in an attempt to effect a shearing action. This expedient is likewise inefiicient for the reason that the cutting edges quickly become dull and the time, expense and difliculty of resharpening the same does not warrant the use of the cutting principle.

Again, in order to meet the problems, relatively thin material has been suggested for the swinging hammers in an attempt to present a combined impact and cutting action. This expedient reduces the mass and, therefore, weight, resulting in an increased amount of deflection of the swingable members with a consequent rapid wearing away of the pivotal connection thereof to the composite unit forming a part of the rotatable apparatus.

In light of the above, it is the primary object of the present invention to provide apparatus of the aforementioned character that alleviates all of the problems heretofore experienced, and to provide a machine that permits the use of relatively thin material in the chopping devices while, at'the same time, avoiding excessive pivoting thereof about their individual axes as the result of meeting the resistance of heavy loads.

An equally important object of the present invention is to provide apparatus having the attributes just above mentioned, while, at the same time, eliminating the necessity of excessive power requirements to operate the same.

An extremely important object, in addition to the above, is to provide a chopper for straw or the like having unique, individual components that are not only inexpensive to manufacture, but easily and quickly assembled and readily removed for replacement from time to time as the need may arise.

In carrying out the aforementioned objects, the phenomena of centrifugal force, as well as the swinging pendulum, have been kept in mind and, therefore, in order to permit the use of relatively thin knives so as to take advantage of the cutting effect thereof and, at the same time, utilize impact forces, all without including the aforementioned defects and disadvantages, the chopping devices have been loaded by use of stop means to hold the same deflected counter to the direction of rotation and away from the normally radial position to which the same tend to swing during rotation of the apparatus.

The way in which this has been accomplished, and the manner of meeting all of the objects above enumerated, will be made clear or become apparent during the course of the following specification, reference being had to the accompanying drawings, wherein:

Fig. 1 is a fragmentary, plan view of a straw chopper made pursuant to my present invention.

Fig. 2 is a fragmentary, cross-sectional view taken on line 22 of Fig. 1.

Fig. 3 is an elevational View of one of the units that is fastened to the shaft of the rotatable apparatus shown in Figs. 1 and 2.

Fig. 4 is a plan view of the unit shown in Fig. 3; and

Fig. 5 is a view similar to Fig. 4 showing a modified form of chopping device, illustrated separate from its attaching fixture.

The purpose and manner of use of the straw chopper forming the subject matter of the instant invention may be substantially the same as disclosed in the D. L. Adams patent, No. 2,708,582, issued May 17, 1955; therefore, the disclosure of said patent is incorporated herein by reference for a better understanding of the instant invention as may be needed.

It is suflice to point on that open top hopper 10 is attached to the combine inposition to receive the straw emanating therefrom and the rotatable apparatus 12, forming the subject matter of the present invention, may be driven from the combine through use of a driven pulley 14 secured to shaft 16 forming a part of the apparatus 12.

Apparatus 12 is mounted within the hopper 10 with the shaft 16 journalled in end walls 18 of hopper 10. The chopped straw is discharged through outlet 20 in the hopper 10 when the apparatus 12 is rotated in the direction of the arrows in Fig. 2. Adjustable deflector 22 and adjustable deflectors 24, form no part of the instant invention and if used, the same may take the form shown in the above patent and be used substantially as therein described. Similarly, inwardly projecting protuberances 26 may be provided to cooperate with the apparatus 12 in substantially the same way as provided in the said Adams patent.

In addition to the shaft 16, the rotatable apparatus 12 includes a plurality of identical elements or chopping devices 28, each of which includes an arm 30 and a knife 32. Each device 28 is also provided with a mount broadly designated by the numeral 34, in the nature of a U- shaped fixture that is clamped directly to the shaft 16. Consequently, each mount or fixture 34 has a bight 36 and a pair of spaced legs 38 and 40, it being seen that the same may be inexpensively made from an initially flat sheet of lightweight material.

Each of the legs 38 and 40 is provided with a notch 42 for clearing the shaft 16 when the mounts 34 are rigidly clamped to the said shaft 16.

The manner of attachment of the fixtures 34 to the shaft 16 is unique and to this end, therefore, each bight 36 is provided with a pair of spaced openings 44 and 46 for receiving suitable fasteners such as bolts 48, one on each side respectively of the shaft 16. The fixtures 34 are arranged in opposed pairs with the legs 38 and 40 thereof interleaved in the manner best seen in Fig. 2 of the drawings. Thus, the opening 44 of one fixture 34 and the opening 46 of the other, adjacent fixture 34, receive one of the bolts 48 and the same arrangement is provided on the opposite side of shaft 16. The relatively short edges 59 of the substantially triangular legs 38 and 40, bear against the bights 36 of the opposed corresponding fixtures 34 when each pair of fixtures 34 is clamped to the shaft 16, thereby holding the bights 36 of each pair of fixtures 34 in parallelism. Noteworthy at this juncture is the fact that said bights 36, forming one wall of the fixtures 34, are normal to a plane passing through, and parallel to the axis of rotation of shaft 16.

It is seen also in Figs. 1 and 2 that the several pairs of fixtures 34 are spaced throughout the length of the shaft 16 in staggered relationship therearound and that they are all joined together by a plurality of elongated bars 52 parallel with the axis of rotation of shaft 16 and spaced radially therefrom.

Bars 52 are transversely L-shaped and, therefore, each bar 52 bears directly against the outermost faces of the bights 36. Bolts 48 pass through the bars 52 and clamp the same in place; accordingly, each fixture 34 has a pair of the bars 52 in engagement therewith. Bars 52 prevent any tendency of the fixtures 34 to shift longitudinally of the shaft 16 or twist circumferentially therearound, but more important, the bars 52 serve to prevent entanglement of the straw around the shaft 16.

The arms 30 of the devices 28 are swingably mounted on their corresponding fixtures 34 between the legs 38 and 40 thereof and, to this end, each of the legs 38 and 40 is provided with an inwardly extending, perforated boss 54 as best seen in Fig. 4. The innermost ends of the arms 30 are received between the bosses 54 and pivot means in the nature of bolts 56 are provided for swingably attaching the arms 30 to the legs 38 and 40.

While the arms 30 are free to swing about the pivot means 56 in a direction counter to the direction of rotation of the apparatus 12, the swinging movement thereof in the opposite direction is limited by an edge 58 on the arms 30 that engages the proximal bight 36, such walls 36 thereby serving as stop means for the arms 30. Note worthy, as best seen in Fig. 2, is the fact that when the edges 58 are in engagement with the walls 36, arms 30 arch outwardly and rearwardly therefrom in a direction counter to the direction of rotation of the apparatus 12.

The chopping knives 32 are attached to the outer ends of the arms 30 through use of carriage bolts 60, the polygonal shanks thereof being fitted within similarly shaped openings in arms 30 and knives 32. Knives 32 are additionally held against swinging movement relative to arms 30 by a lateral extension 62 on the inner ends of the knives 32 engaging the concave edges of the arms 30.

It is clear also in the drawings that each of the knives 32 is provided with a terminal end portion 64 that is not only bent laterally out of the plane of the arms 30, but is slightly twisted longitudinally thereof. This increases the effective widths of the knives 32 so that in the aggregate they substantially span the full length of the apparatus 12 as best seen in Fig. l. The straw is acted upon by the longitudinal edges of the knives 32; therefore, by virtue of the releasable attachment of the knives 32 to the arms 30 through use of bolts 60, said knives 32 may be reversed when one of the longitudinal edges becomes sufficiently worn away to make it desirable to reverse the same.

It is now obvious that all of the components of the apparatus 12 which are clamped to the shaft 16, may be made from relatively lightweight, inexpensive material and that the same may be easily, quickly and inexpensively stamped and formed into the shapes and configurations above described. Similarly, replacement of the knives 32 is simple and inexpensive.

More important however, is the feature of the instant invention having to do with the way in which the knives 32 are loaded. By way of explanation of the use of such material it is to be pointed out that in all structures of this type, centrifugal force tends to swing hingedly mounted hammers to a position extending radially from the axis of rotation of the main shaft. Thus, it is apparent that when apparatus 12 rotates clockwise, viewing Fig. 2, such forces will likewise cause the arms 30 to swing clockwise about their individual pivots 56 to a point where the edges 58 bear tightly against the walls or bights 36. Manifestly, if the walls 36 were not provided within the path of swinging movement of the arms 30, they would swing still farther in a clockwise direction; accordingly, through use of such stop means for the arms 30, they are held in a retracted position and not permitted to swing by centrifugal force to the position which the same would normally assume.

By virtue of such construction, greater resistance is required to cause the arms 30 to swing counterclockwise from the normal position engaging bights 36 than would be needed to deflect such arms 30 in an anti-clockwise direction if the arms 30 were permitted to assume a normal position under the influence of centrifugal force.

During use of the chopper therefore, as the knives 32 meet the resistance of the straw, they will not deflect rearwardly about their pivots 60 as often and the wear about the pivots 56 will be appreciably reduced.

It now becomes obvious that, by virtue of such loading of the devices 28, it is not necessary to provide a great amount of mass as has heretofore been required in order to effect a chopping action by using impact principles. By the same token, it is possible to use relatively lightweight materials in the arms 30 since the same will not quickly wear away about the pivot means 56 because of constant repeated deflection.

Furthermore, it is possible to combine in the apparatus, the principle of a cutting action since knives 32 can be made from relatively thin material and the longitudinal cutting edges of the knives 32 need not be thick and blunt. Attention is specifically called to the relatively thin cutting edges of the portion 64 of the knives 32 which require no sharpening. Manifestly, the centrifugal force is greater than the cutting force and while the cutting devices 28 deflect counterclockwise as a result of an obstruction, thereby preventing the breaking of the knives 32 and choking of the chopper, nonetheless, elements 28 are capable of passing through relatively heavy bunches of straw without deflecting in that manner and without need of excessive power requirements. In fact, these features, coupled with the fact that the entire unit 12 is relatively light, make it possible to substantially reduce the power requirements of the chopper.

A basic advantage of the rotor 12 is the fact that its wearing parts are locked into a fixed position during normal use, resulting in long endurance and satisfactory performance. Its construction also necessitates but a minimum amount of balancing since the parts thereof are uniform and no Welding is required. It folds readily and is, therefore, convenient for shipping, and the simple way in which the brackets or mounts 34 are attached to the rotor shaft 16, is a definite advantage. They can be individually removed without need of disassembly of the entire apparatus 12.

In Fig. 5 it is seen that the same effect may be attained in a chopping device 128 that includes an arm 130 and a knife 132. Blade 132 is rectangular but is not laterally bent as in blade 32. And, in lieu of extension 62, two fasteners 160 are employed to attach the same to arm 130. A terminal end portion 131 is provided in arm 130 by bending the same laterally and it is to this portion 131 that blade 132 is releasably fixed.

Having thus described the invention what is claimed as new and desired to be secured by Letters Patent is:

1. In a rotatable apparatus, a shaft; a plurality of chopping devices; a number of mounts for attaching said devices to the shaft, each including a pair of elongated fixtures engaging the shaft in diametrically opposed relationship and extending radially therefrom in opposite directions, each fixture being transversely U-shaped, presenting a pair of legs and a bight, the bights being parallel, each leg having a shaft clearance notch, said legs being in interleaved relationship, and said shaft being between the bights; means pivotally securing a device to each fixture respectively between the legs thereof; a number of elongated bars parallel with the shaft and engaging said bights; and a pair of elongated fasteners for each mount respectively, one on each side respectively of the shaft and extending through the bights in perpendicular relationship thereto, said fasteners clamping the legs to the shaft and the bars to the mounts, each device including an arm normally engaging the proximal bight and swingable away from said proximal bight about its pivot.

2. In a rotatable apparatus, a shaft; a plurality of chopping devices; a number of mounts for attaching said devices to the shaft, each including a pair of elongated fixtures engaging the shaft in diametrically opposed relationship and extending radially therefrom in opposite directions, each fixture being transversely U-shaped, presenting a pair of legs and a bight, the bights being parall l, each leg having a shaft clearance notch, said legs being in interleaved relationship, and said shaft being between the bights; means pivotally securing a device to each fixture respectively between the legs thereof; a number of elongated bars parallel with the shaft and engaging said bights; and a pair of elongated fasteners for each mount respectively, one on each side respectively of the shaft and extending through the bights in perpendicular relationship thereto, said fasteners clamping the legs to the shaft and the bars to the mounts, each device including an arm normally engaging the proximal bight and swingable away from said proximal bight about its pivot, each arm being arched away from the proximal bight in a direction counter to the normal direction of rotation of the apparatus.

3. In a rotatable apparatus, a shaft; a plurality of chopping devices; a number of mounts for attaching said devices to the shaft, each including a pair of elongated fixtures engaging the shaft in diametrically opposed re1ationship and extending radially therefrom in opposite directions, each fixture being transversely U-shaped, presenting a pair of legs and a bight, the bights being parallel, each leg having a shaft clearance notch, said legs being in interleaved relationship, and said shaft being between the bights; means pivotally securing a device to each fixture respectively between the legs thereof; a number of elon- 6 gated bars parallel with the shaft and engaging said bights; and a pair of elongated fasteners for each mount respectively, one on each side respectively of the shaft and extending through the bights in perpendicular relationship thereto, said fasteners clamping the legs to the shaft and the bars to the mounts, each device including an arm nor* mally engaging the proximal bight and swingable away from said bight proximal about its pivot, and a knife secured to each arm respectively remote from the mounts.

4. In a rotatable apparatus, a shaft; a plurality of chopping devices; a number or" mounts for attaching said devices to the shaft, each including a pair of elongated fixtures engaging the shaft in diametrically opposed relationship and extending radially therefrom in opposite directions, each fixture being transversely U-shaped, presenting a pair of legs and a bight, the bights being parallel, each leg having a shaft clearance notch, said legs being in interleaved relationship, and said shaft being between the bights; means pivotally securing a device to each fixture respectively between the legs thereof; a number of elongated bars parallel with the shaft and engaging said bights; and a pair of elongated-fasteners for each mount respectively, one on each side respectively of the shaft and extending through the bights in perpendicular relationship thereto, said fasteners clamping the legs to the shaft and the bars to the mounts, each device including an arm normally engaging the proximal bight and swingable away from said bight proximal about its pivot, and a knife secured to each arm respectively remote from the mounts, each knife having a terminal end extending laterally out of the plane within which the proximal arm rotates.

5. In a rotatable apparatus, a shaft; a plurality of chopping devices; a number of mounts for attaching said devices to the shaft, each including a pair of elongated fixtures secured to the shaft in diametrically opposed relationship and extending radially therefrom in opposite directions, each fixture being transversely U-shaped, presenting a pair of legs and a bight, the bights being parallel and said shaft being between the bights; and means pivotally securing a device to each fixture respectively between the legs thereof, each device including an arm normally engaging the proximal bight between the corresponding legs of the latter and swingable away from said proximal bight above its pivot, each of said arms being arched away from the proximate bight in a direction counter to the normal direction of rotation of the apparatus.

6. The invention of claim 5, and a knife secured to each arm respectively remote from the mounts.

7. The invention of claim 6, each knife having a terminal end extending laterally out of the plane within which the proximal arm rotates.

References Cited in the file of this patent UNITED STATES PATENTS 1,512,484 Porter Oct. 21, 1924 1,871,489 Ammon Aug. 16, 1932 2,753,674 Cunningham et a1. July 10, 1956 2,835,298 Collins May 20, 1958 2,841,946 Skromme et al July 8, 1958 2,938,326 Lundell May 31, 1960 

